While we’re confident in our calculations and data sets, it’s worth repeating that determining how many people experience day, night, or twilight at any one moment is a rather messy business.
For one, the world’s population isn’t static. It changes over time, and in some locations, it does so at a different pace than in others. We based our calculations on the best population data sets available—but they are from 2020.
What’s more, the margins are minuscule. While our algorithms did identify a specific instant when most people get some degree of sunlight—11:02 UTC on June 23—the population numbers for the days on either side of this date are just a tiny fraction smaller. We’re talking a few tens of thousands of people—peanuts compared to the world’s population.